I don't know much about quail...
However for chickens salmonella is commonly part of there normal gut flora and not harmful to the chickens, in fact it may be beneficial. Also eggs are always free of salmonella, unless contaminted by chicken poop containing salmonella.
Just wash you hands after handlelng the birds or there poop. Eggs that are contaminated with poop should be washed before cracked open.
This is not true. Salmonella can actually infect the ovaries of a chicken hen and it actually infects the egg before the shell is even formed over it. That's why they say you don't eat things like raw brownie batter when you use store bought eggs to make it - cooking kills the salmonella but eating it raw puts you at risk.
This same thing doesn't happen in quail, however, because their eggs contain an increased amount of lysozyme, which is harmful to bacteria.